The aim of the project in order to test Hanihara's 'dual structure model' for the formation of the modem Japanese has carried out intensively. There is, however, a contradiction in the origin of the indigenous Jomon (Neolithic age) population. In terms of skeletal morphology, Jomon people show strong resemblances to Southeast Asians. However, analysis of the genetic diversity of the modem Asians has shown that the Ainu - who are thought to be the direct descendants of the Jomon people - are genetically closer to Northeast Asians than to Southeast Asians.It has been assumed from skeletal morphology that the immigrant Yayoi (Bronze age) people originated in Siberia from where they came to Japan via Korea or China. This assumption is also strongly supported by the genetic evidence from modern and ancient DNA of Asians. It is not clear, however, exactly where these people were living prior to their arrival in the Japanese Islands.From the distribution of the skeletal material found across Japan, it can be seen that the immigrant groups arrived in north Kyushu and Yamaguchi and then expanded north and south. They expanded through western Japan in the Early Yayoi and had reached the Tohoku region by the Late Yayoi phase. However, they did not move into the periphery of the Kyushu until the Proto-historic period and Hokkaido until the Early Modern period. This process of immigration and expansion is reflected in modern genetic diversity, with many traits showing a decline in frequency to the northeast and to the southwest of the Japanese Islands.In conclusion, the results of the project agree completely with the predictions of the dual structure hypothesis that population strongly influenced by the Yayoi-period immigrants form the major component of the Japanese people in Honshu and other main islands.